I knew I had seen a picture of vambraces similar to the ones you made somewhere. This pic is from G.C. Stones venerable and somewhat outdated "Glossary of the Construction, Decoration, and Use of Arms and Armor in All Countries and in All Times". Unfortunately Stone doesn't mention when these vambraces were made and in what part of India where they used.
This picture is also from the same book, surprisingly it's the only picture I have that shows the back of a krug:
